/* Front-page mark, opted into per page, never on a lesson page.

   A lambda from CMU Serif Roman, the serif companion of the body font, drawn as
   a path because the site ships CMU Bright only. Drawn as a mask rather than a
   background image, so the colour comes from --bs-primary and one asset serves
   both modes. */

.lambda-mark {
  position: fixed;
  inset: 0;
  z-index: -1;
  pointer-events: none;          /* never eat a click meant for the page */
  background-color: var(--bs-primary, #536681);
  -webkit-mask-image: url("data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20viewBox%3D%2228%20-696%20442%20706%22%3E%3Cg%20transform%3D%22scale%281%2C-1%29%22%3E%3Cpath%20d%3D%22M28%20657C28%20646%2035%20619%2066%20619C75%20619%2084%20621%2091%20621C180%20621%20222%20475%20222%20468C222%20464%20221%20458%20219%20451C105%20135%2029%2032%2029%2011C29%201%2041%200%2051%200H83C91%200%20100%200%20106%207C113%2015%20184%20153%20259%20352C333%20110%20379%20-10%20434%20-10C457%20-10%20470%209%20470%2028C470%2058%20442%2063%20432%2067C378%2090%20333%20190%20266%20418C233%20531%20192%20696%2081%20696C36%20696%2028%20672%2028%20657Z%22%2F%3E%3C%2Fg%3E%3C%2Fsvg%3E");
          mask-image: url("data:image/svg+xml,%3Csvg%20xmlns%3D%22http%3A%2F%2Fwww.w3.org%2F2000%2Fsvg%22%20viewBox%3D%2228%20-696%20442%20706%22%3E%3Cg%20transform%3D%22scale%281%2C-1%29%22%3E%3Cpath%20d%3D%22M28%20657C28%20646%2035%20619%2066%20619C75%20619%2084%20621%2091%20621C180%20621%20222%20475%20222%20468C222%20464%20221%20458%20219%20451C105%20135%2029%2032%2029%2011C29%201%2041%200%2051%200H83C91%200%20100%200%20106%207C113%2015%20184%20153%20259%20352C333%20110%20379%20-10%20434%20-10C457%20-10%20470%209%20470%2028C470%2058%20442%2063%20432%2067C378%2090%20333%20190%20266%20418C233%20531%20192%20696%2081%20696C36%20696%2028%20672%2028%20657Z%22%2F%3E%3C%2Fg%3E%3C%2Fsvg%3E");
  -webkit-mask-repeat: no-repeat;
          mask-repeat: no-repeat;
  /* Off right and bleeding past the edge, so it frames rather than underlays. */
  -webkit-mask-position: 88% 46%;
          mask-position: 88% 46%;
  -webkit-mask-size: auto 78vh;
          mask-size: auto 78vh;
  opacity: .05;
}

/* On a phone the glyph would sit across the text at this size. */
@media (max-width: 600px) {
  .lambda-mark {
    -webkit-mask-size: auto 42vh;
            mask-size: auto 42vh;
    -webkit-mask-position: 92% 88%;
            mask-position: 92% 88%;
  }
}

/* No prefers-reduced-transparency guard. That setting is for transparency you
   read THROUGH, and this sits behind the margin. A guard was tried and it just
   hid the mark on any Mac with Reduce transparency on. */